Changed ColorPutter in preparation for Bloodlust & Petrify effects

client/battle/BattleAnimationClasses.cpp

@@ -628,7 +628,7 @@ void FadingAnimation::nextFrame()
 	uint8_t blue   = stack->cloned ? 128 : 0;
 	uint8_t alpha  = CSDL_Ext::lerp(from, dest, progress);
 
-	ColorShifterMultiplyAndAdd shifterFade ({factor, factor, factor, alpha}, {0, 0, blue, 0});
+	ColorShifterRange shifterFade ({0, 0, blue, 0}, {factor, factor, 255, alpha});
 	stackAnimation(stack)->shiftColor(&shifterFade);
 
 	if (progress == 1.0f)

client/battle/BattleStacksController.cpp

@@ -76,10 +76,10 @@ BattleStacksController::BattleStacksController(BattleInterface & owner):
 	amountNegative   = IImage::createFromFile("CMNUMWIN.BMP");
 	amountEffNeutral = IImage::createFromFile("CMNUMWIN.BMP");
 
-	static const ColorShifterMultiplyAndAddExcept shifterNormal  ({150,  50, 255, 255}, {0,0,0,0}, {255, 231, 132, 255});
-	static const ColorShifterMultiplyAndAddExcept shifterPositive({ 50, 255,  50, 255}, {0,0,0,0}, {255, 231, 132, 255});
-	static const ColorShifterMultiplyAndAddExcept shifterNegative({255,  50,  50, 255}, {0,0,0,0}, {255, 231, 132, 255});
-	static const ColorShifterMultiplyAndAddExcept shifterNeutral ({255, 255,  50, 255}, {0,0,0,0}, {255, 231, 132, 255});
+	static const ColorShifterRangeExcept shifterNormal  ({0,0,0,0}, {150,  50, 255, 255}, {255, 231, 132, 255});
+	static const ColorShifterRangeExcept shifterPositive({0,0,0,0}, { 50, 255,  50, 255}, {255, 231, 132, 255});
+	static const ColorShifterRangeExcept shifterNegative({0,0,0,0}, {255,  50,  50, 255}, {255, 231, 132, 255});
+	static const ColorShifterRangeExcept shifterNeutral ({0,0,0,0}, {255, 255,  50, 255}, {255, 231, 132, 255});
 
 	amountNormal->adjustPalette(&shifterNormal);
 	amountPositive->adjustPalette(&shifterPositive);
@@ -213,7 +213,7 @@ void BattleStacksController::stackAdded(const CStack * stack, bool instant)
 
 	if (!instant)
 	{
-		ColorShifterMultiplyAndAdd shifterFade ({255, 255, 255, 0}, {0, 0, 0, 0});
+		ColorShifterRange shifterFade ({0, 0, 0, 0}, {255, 255, 255, 0});
 		stackAnimation[stack->ID]->shiftColor(&shifterFade);
 
 		owner.executeOnAnimationCondition(EAnimationEvents::HIT, true, [=]()

client/gui/SDL_Extensions.h

@@ -167,37 +167,44 @@ public:
 };
 
 /// Generic class for palette transformation
-/// formula:
-/// result = input * factor + added
-class ColorShifterMultiplyAndAdd : public ColorShifter
+/// Applies linear transformation to move all colors into range (min, max)
+class ColorShifterRange : public ColorShifter
 {
-	SDL_Color added;
+	SDL_Color base;
 	SDL_Color factor;
 
 public:
-	ColorShifterMultiplyAndAdd(SDL_Color factor, SDL_Color added) :
-		factor(factor),
-		added(added)
-	{}
+	ColorShifterRange(SDL_Color min, SDL_Color max) :
+		base(min)
+	{
+		assert(max.r >= min.r);
+		assert(max.g >= min.g);
+		assert(max.b >= min.b);
+		assert(max.a >= min.a);
+		factor.r = max.r - min.r;
+		factor.g = max.g - min.g;
+		factor.b = max.b - min.b;
+		factor.a = max.a - min.a;
+	}
 
 	SDL_Color shiftColor(SDL_Color input) const override
 	{
 		return {
-			uint8_t(std::min(255.f, std::round(input.r * float(factor.r) / 255.f + added.r))),
-			uint8_t(std::min(255.f, std::round(input.g * float(factor.g) / 255.f + added.g))),
-			uint8_t(std::min(255.f, std::round(input.b * float(factor.b) / 255.f + added.b))),
-			uint8_t(std::min(255.f, std::round(input.a * float(factor.a) / 255.f + added.a)))
+			uint8_t(base.r + input.r * factor.r / 255),
+			uint8_t(base.g + input.g * factor.g / 255),
+			uint8_t(base.b + input.b * factor.b / 255),
+			uint8_t(base.a + input.a * factor.a / 255),
 		};
 	}
 };
 
 /// Color shifter that allows to specify color to be excempt from changes
-class ColorShifterMultiplyAndAddExcept : public ColorShifterMultiplyAndAdd
+class ColorShifterRangeExcept : public ColorShifterRange
 {
 	SDL_Color ignored;
 public:
-	ColorShifterMultiplyAndAddExcept(SDL_Color factor, SDL_Color added, SDL_Color ignored) :
-		ColorShifterMultiplyAndAdd(factor, added),
+	ColorShifterRangeExcept(SDL_Color min, SDL_Color max, SDL_Color ignored) :
+		ColorShifterRange(min, max),
 		ignored(ignored)
 	{}
 
@@ -205,7 +212,25 @@ public:
 	{
 		if ( input.r == ignored.r && input.g == ignored.g && input.b == ignored.b && input.a == ignored.a)
 			return input;
-		return ColorShifterMultiplyAndAdd::shiftColor(input);
+		return ColorShifterRange::shiftColor(input);
+	}
+};
+
+class ColorShifterGrayscale : public ColorShifter
+{
+public:
+	SDL_Color shiftColor(SDL_Color input) const override
+	{
+		// Apply grayscale conversion according to human eye perception values
+		uint32_t gray = static_cast<uint32_t>(0.299 * input.r + 0.587 * input.g + 0.114 * input.b);
+		assert(gray < 256);
+
+		return {
+			uint8_t(gray),
+			uint8_t(gray),
+			uint8_t(gray),
+			input.a
+		};
 	}
 };